The pion structure function is investigated in a simple pseudo-scalar
coupling model of pion and constituent quark fields. The imaginary part of the
forward Compton scattering amplitude is evaluated. We show that the
introduction of non-perturbative effects, linked through a cut-off to the size
of the pion, allows the reproduction of important features of the pion quark
distribution function.Comment: 3 pages, 1 figur